Journal of computational fluids engineering (한국전산유체공학회지)

Korean Society of Computational Fluids Engineering (한국전산유체공학회)
권호 표지

HEAT TRANSFER CHARACTERISTICS IN A FAST PYROLYSIS REACTOR FOR BIOMASS

바이오매스 급속열분해 반응기내 열전달 특성

  • 최항석 (한국기계연구원, 그린환경에너지기계연구본부)
  • Received : 2009.10.09
  • Accepted : 2009.12.18
  • Published : 2010.03.31
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Abstract

The characteristics of flow and heat transfer in a bubbling fluidized bed are investigated by means of computational fluid dynamics (CFD). To simulate two-phase flow for the gas and solid flows, Eulerian-Eulerian approach is applied. Attention is paid for a heat transfer from the wall to fluidized bed by bubbling motion of the flow. From the result, it is confirmed that heat transfer is promoted by chaotic bubbling motion of the flow by enhancement of mixing among solid particles. In particular, the vortical flow motion around gas bubble plays an important role for the mixing and consequent heat transfer. Discussion is made for the time and space averaged Nusselt number which shows peculiar characteristics corresponding to different flow regimes.

Keywords

References

  1. 1991, Kunii, D. and Levenspiel, O., Fluidization Engineering, Butterworth-Heinemann, Newton.
  2. 1995, Pence, D.V. et al., "Deterministic Chaotic Behavior of Heat Transfer in Gas Fluidized Beds," J. Heat Transfer, Vol.177, pp.465-472.
  3. 2006, Friedman, J. et al., "Heat Transfer to Small Horizontal Cylinders Immersed in a Fluidized Bed," Trans. ASME, J. Heat Transfer, Vol.128, pp.984-989. https://doi.org/10.1115/1.2345425
  4. 2007, Natale, F.D. et al., "Surface to Bed Heat Transfer in Fluidized Beds: Effect of Surface Shape," Powder Technology, Vol.174, pp.75-81. https://doi.org/10.1016/j.powtec.2007.01.010
  5. 1999, Schmidt, A. and Renz, U., "Eulerian Computation of Heat Transfer in Fluidized Beds," Chemical Engineering Science, Vol.54, pp.5515-5522. https://doi.org/10.1016/S0009-2509(99)00298-5
  6. 2000, Schmidt, A. and Renz, U., "Numerical Prediction of Heat Transfer in Fluidized Beds by a Kinetic Theory of Granular Flows," Int. J. Therm. Sci., Vol.39, pp.871-885. https://doi.org/10.1016/S1290-0729(00)01193-5
  7. 2001, Wachem, B.G.M. et al., "Comparative Analysis of CFD Models of Dense Gas-Solid Systems," AIChE Journal, Vol.47, pp.1035-1051. https://doi.org/10.1002/aic.690470510
  8. 1993, Syamlal, M. et al., "MFIX Documentation Theory Guide," Technical Note, DOE/METC-94/1004, NTIS/DE94000087, U.S. Department of Energy, Office of Fossil Energy, Morgantown Energy Technology Center Morgantown, WV, National Technical Information Service, Springfield, VA.
  9. 2005, Hulme, I. et al., "CFD Modeling and Validation of Bubble Properties for a Bubbling Fluidized Bed," Ind. Eng. Chem. Res., Vol.44, pp.4254-4266. https://doi.org/10.1021/ie049837j
  10. 1988, Syamlal, M. and O'Brien, T.J., "Simulation of Granular Layer Inversion in Liquid Fluidized Beds," Int. J. Multiphase Flow, Vol.14, pp.473-481. https://doi.org/10.1016/0301-9322(88)90023-7